The larynx is a strategically important organ situated at the crossroads of the upper respiratory and digestive tracts, orchestrating swallowing, breathing, coughing and, in humans, voice. The hallmark of many clinically important laryngeal diseases affecting these critical functions is mucosal inflammation. In other parts of the body, the pathogenesis of mucosal inflammatory disease is intimately linked to local immune responses. Chronic laryngitis is a laryngeal disorder that represents a significant clinical problem. Treat progress for this disease is hampered due to limited understanding of the immunological architecture of the larynx and how it changes with physiological and pathological challenges. There is a comprehensive need for an understanding of the interaction between the laryngeal mucosal immune system and inflammatory challenges if new, targeted, diagnostic and therapeutic avenues for chronic laryngitis are to be fully realized. Mucosal immunity is determined by the interaction between the `immunological triad' of epithelial cells, bacteria, and professional immune cells in the epithelium and underlying lamina propria. The goal of this research program is to ascertain, mechanistic insights for components of the triad, by studying gene and protein expression, through a series of in vivo and in vitro experiments. This innovative proposal will map the immunological, including bacterial, architecture of the normal laryngeal mucosa and examine how it is altered in chronic laryngitis as defined by diffuse smoke, reflux and/or focal polypoid change. This will be correlated with the effects of interventions -- altered flora, tobacco and refluxate -- on an in vitro model. Our overarching, long-term hypothesis is that significant laryngeal mucosal challenges leave distinguishing immunological and bacteriological fingerprints. We hypothesize that such fingerprints can be modeled in vitro and such models used to develop and direct future interventions for the prevention and treatment of inflammatory and even malignant diseases of the larynx. Our specific aims are 1) to complete the genetic, proteomic immunological map of the laryngeal mucosa in normal persons and those with chronic laryngitis, 2) to map the laryngeal mucosal bacteriome, including quantification of total eubacterial load and the presence and location of specific species, including helicobacter pylori, within the laryngeal mucosa and lamina propria and 3) to use an in vitro model system to determine the contribution of the bacterial flora of the larynx to its immunological architecture, and how this is influenced by key incident challenges. The development of these maps will have a significant impact on the field of laryngology. We anticipate that the mapping data generated in this project will be highly valuable to other scientists and have included a data sharing plan to make our raw data available to the scientific community. 1